Electrc furnace



Feb. 28, 1928.

A. J. ASCH ELECTRIC FURNACE Filed Feb.4, 1927 INVENTOR HND/WSW @M760/f ATTORNEY WITNESSES @0560 Patented Feb., 28,; ldc

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ANDREW' Jl. ASCE, D?? NEW YRK, N. Y.

rinnc'rnic rommel-i.

lhis invention relates to electric furnaces and has especial reference to electric turnaces such as are used in dentistry. u

Sonie ot the objects et the present invention are: an electric furnace including a heatingl element which may be quickly and easily incorporated, ot comparatiyely long lite, andl when the occasion arisesZ may be replaced Without requiring scrapping ot other parts oi' the furnace; a heating element for an electric furnace oi? comparatively low resistance efi'ective on a comparatively low voltage, and capable of being brought almost instantl)7 into a state ot 1nleandescciice thereby expcditing the completion oi the work; and a heating element in a furnace ol the indicated character for a direct application ot heat in carrying out 'fusing operationsn l/V ith the *toregoing other objects ci the invention will appear from the embodiments ot the invention which, by way ot example, are described in the following specification and illustrated in the accompanying drav'- ing, ,in which Figure 1 is a'V sectional view through an electric furnace embodying lone form of the present invention. o

Fig. 2 is a sectional view taken on the line 2-f ot llig. l.

Fig. 3 is a sectional view through an electric furnace illustrating a modified form o heating means.

Electric furnaces used in. dentistry for carrying out Yfusing operations among other things7 hitherto produced have been found faulty, due to the that the heating means is so incorporated that it is of short life and burns out Without giving much servigs.

l and 2 will be apparent that there is.

snovvn a r nace .l0 including a heat cnamvloer ll termed by a base member of insulating in al such as a high refractory 'composition of silica cuierta. and hollov:n body r ractory of 13 also a big cereal.

Application sled February e, 192'?. Serial No. 165,900.

associated with the base member 12 in such a manner that when the occasion arises it maybe easily replaced. 'lhe said heating means 14 is in the term ot loil, preferably platinum7 and therefore of comparatively low resistance. A piece et platinum toil ot proper dimensions is associated with the base member 12 by providing the base member 12 with spaced holes 15 through which the opposite ends respectively of the piece of platinum foil are respectively extended. 'lhis provides an intermediate major portion 16 within the heatJ chamber l1, and two end port-ions 17. llach of the end portions 17 is secured to the base member l2 by means in the form et a binding post 18 carried by the base member 12, and which is adapted lor eecting an electrical connection therewith of an electrical conductor. The heating means 14 being ol' comparatively low resistance is capable of being brought to a state et incandescence on a low voltage and comparatively great amperage. rlhe proper potential is applied to the heating means M from the usual 110 volt supplied by the use of a transformer indicated at 19 in Fig. 1, which is electrically connected by the binding post 18, as shown.. lnasmuch as the invention resides in the use ot the type ol heating means le shown, any suitable means may be employed for supplying the necessary electrical energy thereto.

Frein the foregoing will be apparent that the heating means is' so incorporated as to be readily replaced when the occasion arises7 from bein0f burned out or for any other reason7 without requiring scrapping ot the part or the furnace With which it is associated. lt is to be noted that the portion 16 is exposed to the interior and will therefore ellectively radiate heat Within the chamber lf. for carrying out fusing operations.

`ln Fig. 3 there is shown a modication in which the heating means is so termed as to maire possible the inclusion oil a platinum matrix for the direct application of heat to, the porcelain to be fused in forming a tooth or portion thereof. The heating ,means in 'this form consists ot two parts 20 of platinum foil which are associated with the base member l2 in a manner similar to that in "which it is accomplished in the preferred form. A platinum matrix 21 has portions i'iliereoE in contact ports 2li to orm I (ill lll

a complete circuit through the heating means. lt Will at once he apparent that when the current is on not only the parte 20 will loecome incandescentn but also the matrix 2l. lt will theretore he possible to apply the heat directly to the porcelain iiidicated at 22, in the olotainment of the desired formation.

ll claim:

l. ln an electric furnace, a heating elen ment comprising a. piece of platinum foil supported within the furnace and having portions thereof extending outwardly of a Wall ot the furnace for the attachment thereto of a source ot current supply.

2. ln an electric furnace, a heating ele ment comprising'a strip ol.2 platinum toil disposed inwardly ot the turnace and supported by a Wall thereof, and having its opposite end portions extending outwardly ot the Wall for the attachment thereto et a source of current supply.,

3. ln an' electric furnace, a heating element comprising a substantially unbroken strip olf/platinum foil trained over an in* terior Wall of the furnace, and having its ends projectingn outwardly through the Wall at the opposite ends thereof 'for attachment thereto ot a source of current supply. i 4t. ln an electric furnace, a heating elenient comprising an independently removable and substantially unbroken length olf' platinum oil trained over an interior Wall ot' the furnace, and having its ends projectingoutwardly through the Wall adjacent the opposite ends thereof for the attachment thereto ot a source ot current Supply.

ANlDRlEl/V J. ASCH. 

